Intravascular intervention treatment is a treatment method of inserting a treatment tool (device) called catheter into a blood vessel, to perform treatment of an affected part generated in the heart, the brain, the liver or the like. For example, in intravascular intervention treatment, the doctor inserts a catheter with a balloon into a narrow segment. Thereafter, for example, the doctor injects liquid into the balloon through the catheter, to expand the balloon. In this manner, the narrow segment is mechanically expanded, and the blood flow is recovered. The catheter with a balloon is extracted out of the body by the doctor, after the liquid in the balloon is absorbed.
In addition, another intravascular intervention treatment using a catheter with a balloon is also performed, to prevent restenosis of the narrow segment expanded with the balloon. In the catheter with a balloon, a metal mesh (stent) is in close contact with the outside of the balloon. In the treatment method, the doctor expands the stent by expanding the balloon, thereafter absorbs the liquid in the balloon, and extracts the catheter out of the body. In this manner, the expanded stent is placed in the narrow segment, to reduce the restenosis rate of the narrow segment.
The intravascular intervention treatment requires movement of the device inserted into the blood vessel to the treatment target region with accuracy. Generally, positioning of the device is performed, with reference to an X-ray image generated and displayed in real time with an X-ray diagnostic apparatus. For this reason, for example, X-ray impermeable metal is attached to two parts (one part in some cases) of the device, as markers indicating the position of the balloon or the stent. The doctor positions the device, with reference to the markers drawn in the X-ray image displayed on the monitor.
However, when intravascular intervention treatment is performed on a blood vessel of an organ that always pulses, such as the heart, or an organ moving with pulsation, the position of the device on the X-ray image always moves. For this reason, positioning the device with reference to the X-ray image becomes a very advanced work for the doctor.
In prior art, a technique of performing moving image display in which the device virtually looks as if the device is stationary is known. In the technique, for example, the marker drawn on sequentially generated X-ray images is tracked, and image transformation is performed such that the position of the marker in each of the X-ray images is the same position as that in the past images. A technique of highlighting the device with high contrast is also known. In the technique, the device is highlighted by, for example, determining an arithmetic mean of images of a plurality of frames in which the position of the marker is corrected to the same position, as a post process.